The present invention relates generally to improvements in water-tight housings and it relates particularly to an improved housing of water-tight construction for receiving therein a camera or various camera mechanisms.
A housing for receiving therein a camera body or various camera mechanisms and serving as an outer casing for the camera, in general, is provided with a comparatively large opening, through which the photographic film may be loaded into or removed from the camera. Because of such a large opening in the housing, a poor hermetic or waterproof condition of the housing occurs. Particularly, in the case where it is desired to provide a flat rectangular opening for the camera, for example, in the case where the camera is of flat rectangular parallelopiped form, and the casing must receive therein such a flat rectangular parallelopiped camera body, or in the case where the casing itself is used as the camera outer casing and the camera employs a 110 sized film-cartridge, a product of Eastman Kodak Company, it has been difficult to impart water-tightness to the casing. For facilitating an understanding of the present invention, reference is made to FIGS. 1 and 2 of the drawings which illustrate an art device wherein reference numeral 2 designates a casing or housing, in which are incorporated various mechanisms of a camera (not shown), such as an exposure control mechanism, a shutter mechanism, etc. A cover 4 is provided for sealing an opening in casing 2, and an annular packing 6 made of a resilient material is fitted on the inner peripheral wall of the cover 4 which is provided with an outer flange. In the condition shown in FIGS. 1 and 2 where cover 4 registers with and engages the opening in casing 2, packing 6 is sealingly embraced between the confronting faces of the casing inner wall and cover 4, thereby preventing ingress of water into the casing. In order to provide an improved water-tight condition, annular packing 6 is of somewhat greater diameter than clearance between the confronting faces of the inner wall of casing 2 and cover 4, so that when the cover is coupled to the casing, the annular packing is free to deform under compression due to its elasticity, in the manner shown in FIG. 1. The camera body including casing 2 is so constructed as to receive therein a 110 sized film cartridge, a product of Eastman Kodak Company, and the aforesaid opening has a flat rectangular profile as shown in FIG. 2, for ease of insertion or removal of the film cartridge into or from the camera body. The major sides 2a and 2b delineating the housing rectangular opening are of much greater length than the minor sides thereof. When cover 4 and casing 2 are intercoupled, the inner peripheral wall of casing 2 is urged outwardly under the influence of the restoring force of annular packing 6, particularly major side walls 2a and 2b, which are undesirably outwardly flexed in the direction of arrows A and B in FIG. 2. This is due to fact that the biasing force of annular packing 6 acts on the angular portions at which the long sides are joined with the housing short sides, as a force in spreading the angular portions, and that such a force is concentrated at the mid portions of the long sides of the opening which are of minimum flexing strength or resistance. Consequently, a gap 8 occurs between annular packing 6 and the inner wall of casing 2, with the consequent failure to provide a watertight seal for the casing.
Furthermore, in the construction described above, the portion of casing 2, which defines the access opening, suffers from deformation during long service and eventually assumes an outward curve. Thus, a gap is formed between the packing and the casing, resulting in poor water-tight condition therebetween.